Artificial gravity : evaluation of adaptation to head movements during short-radius centrifugation using subjective measures

Abstract

An experiment was performed to determine the ability of humans to adapt, and retain adaptation to out-of-plane head movements made during short-radius centrifugation. The hypothesis for the experiment was as follows: Repeated exposure to a series of yaw head movements made during short-radius centrifugation at 23rpm, (with the subject lying supine and the head on the axis of rotation) will result in a decrease in the magnitude of inappropriate perceived self-motion sensations and severity of motion sickness. Verbal accounts of perceived pitch, motion-sickness scores and computer animations of subjective sensations were obtained from eight subjects, during three sessions performed at the following intervals: day one, day two and day eight. Verbal accounts of perceived pitch obtained during rotation and post-experiment motion-sickness scores provide clear evidence of adaptation to the stimulus between days one and two, and some retention of adaptation to day eight. Computer animations of subjective sensations obtained after the experiment and motion-sickness scores reported during the experiment do not provide conclusive evidence of adaptation, or retention of adaptation. The validity of these techniques were explored, along with a qualitative analysis of the results.